Thoughts on the evolution of wireless networks and mobile web 2.0

A little rant today on new buildings and coverage issues as I keep hearing such reports with increasing frequencies:

When GSM was launched in the 1990's the windows of most buildings were made of glass and while there was some signal loss through them, by and large things worked pretty well. Over the last couple of years however, new buildings, especially offices, are equipped with heat insulating windows that don't only keep the heat or cold out but also radio waves. Their effect is pretty dramatic. Excellent coverage outside the building, no coverage whatsoever inside the building. Hotels, offices, shopping malls, you name it, it's getting more difficult to get coverage into those buildings from macro cells on the outside. While shopping malls are often equipped with indoor coverage via repeaters or small cells, hotels and office buildings or usually not. An exception I have noticed are 4+ star hotels in Asia while their European counterparts usually don't bother. Sure, there are solutions for this that work great such as repeaters, distributed antenna systems, small cells, femto cells, etc. but they all require active interaction between network operators and the owner of the buildings, i.e. extra work. Extra work many building owners are so far unwilling to do. I wonder how much critical mass it will take in terms of new buildings before network operators are taking a pro-active approach to this!?

One of the few positive outcomes of the ongoing spying scandal is that German email hosters have announced to improve security for email exchanged between them by introducing encryption. In addition, many of them have now upgraded their security for SMTP, POP and IMAP connectivity to their customers as well. When I recently run a trace of the email traffic between me and my provider I was positively surprised to see that they now use TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (0xc014) as a cipher suite with clients that support it (e.g. Thunderbird in my case on my notebook and K9 email on Android). ECDH stands for Elliptic Curve Diffie Hellman, an algorithm that to generate temporary cipher keys which can't be reconstructed even if the SSL certificate used during session establishment falls into the wrong hands later on. Hence it's called 'Perfect Forward Secrecy'. For details of what this means, have a look at this previous post. While my data is still stored on the server as clear text this at least prevents casual eavesdropping by those analyzing all data that runs through a transmission link. And that suits me just fine!

Back in my College days I had a course on computer graphics and how elements such as windows, buttons, input boxes, etc. etc. end up on the screen (both on the desktop and on mobile from today's perspective) and how they can overlap and disappear behind each other. But that's been some time ago so I was quite glad to have stumbled over a quick refresher on the difference of X and Wayland here. The first part of the post is quite easily understandable for those with a general background of how a desktop is rendered while the second part is quite a deep dive. But even if you don't want to go down that deep the post is still worth reading.

It's a bit of a paradox, I'm using the 32 bit version of Ubuntu on the PC while on one of my mobile phones a 64 bit based operating system is in operation.

There is one particular reason that made me still use the 32 bit version of Linux on my current notebook. When I set it up around two years ago I wasn't sure how backwards compatible the 64 bit version of the OS would be for 32 bit Windows programs I still have to use every now and at then for compatibility reasons via Wine. Perhaps it's no issue at all but I saw now risk or disadvantages of staying on 32 bits as Linux unlike Windows 7, which is restricted to 3GB on 32 bits, can still use the full 8 GB of RAM on my machine via PAE (Physical Address Extension). Each program is restricted to 4 GB of addressable memory but on a notebook not running enterprise scale applications that is not an issue at all. But it's definitely a kludge to ensure backwards compatibility.

As there are fewer reasons on mobile platforms to be backwards compatible it is quite a logical step to start the transition to 64 bits now. Some devices such as tablets already have 2GB of RAM inside today and going beyond the 4GB threshold is likely not far away anymore. So it's a good thing companies are thinking about 64 bits now instead of coming up with things like PAE on mobile just for the sake of dragging along old stuff.

So there we go, I'll have to live with my 32 bit PC versus 64 bit mobile paradox for just a little while longer.

Observation of the day: I find it quite interesting how Apple continues to gain mind share and users. When I was recently having breakfast in Silicon Valley, most people in the café hunched over a Macbook. My count were 7 Macs vs. only 2 Windows notebooks. Sure, Silicon Valley is a special case but I still think it is not much of an amplification of a general trend that can be observed.

It is interesting how getting connected in the US as a visitor via cellular has changed over the years from one extreme to the other. While Internet access enabled prepaid SIM cards where available in the past 5 to 6 years in many countries around the world I struggled for many years to get the same thing in the US. At some point AT&T offered mobile data on prepaid SIMs but one had to find an AT&T store and then fiddle with a pretty rough web front-end to activate a data option. Not ideal.

But things have significantly changed recently. When preparing for a business trip to the US I noticed that a number of MVNOs (virtual network operators) have sprung up that offer prepaid SIMs for mobile Internet access specifically for international visitors. Here's a PC Mag article that gives a good overview. I opted for a Ready SIM 500 MB data only SIM for around $20 (including shipping) that remains active for 14 days after first activation. Other options that include voice and and a bigger data bucket are also avaialble. It's a use and throw away SIM as there's not even an option to top-up option. That probably means that have a pretty lean back-end system :-)

The only catch was that I had to find a mobile device that supported Wi-Fi tethering and the US 3G frequency bands of the network used by that MVNO, which were the 1900 MHz and AWS (1700/2100 MHz) bands. That's not so easy anymore as current mobile devices often sacrifice 3G bands for LTE and the AWS band was never very popular for 3G in devices outside North America in the first place. But I managed to get hold of one and I decided to order a 'Ready SIM' to my hotel as there wasn't enough time anymore for international shipping. Next time I'll order it a bit sooner so I can already use it at the airport.

In practice it only took a few minutes after inserting the SIM card for the first time before the data option was activated. In terms of speed I couldn't complain but the network managed to kill two different kinds of VPN tunnels regularly. It's a bit of a nuisance and I haven't experienced that in other countries before but I could live with it for a couple of days.

So while there is room for improvement I really enjoyed the freedom of having Internet access when out and about without roaming charges and it also spared me the $12.99 Wi-Fi charges the hotel wanted to charge me per day. I like competition.

Like most multi device users I need to transfer files between my notebook and mobile devices every now and then. As I travel a lot, I have so far abstained from installing a file synchronization client on my PC or my mobile devices as I wasn't quite sure how to ensure that the synchronization process doesn't eat into my roaming data bucket. Also, I don't want my data traversing the data center of a commercial cloud storage provider for privacy reasons. My solution was therefore to transfer files via Bluetooth between devices when they are at close range to each other. For a file or two of a few megabytes such as a camera image that approach works quite well. But for larger files such as PDF documents with a size of tens and hundreds of megabytes or larger file connections, Bluetooth is just too small. And then there are mobile devices out there that can't send files via Bluetooth at all.

For these reasons I decided at some point to give Internet based file synchronization mobile apps a closer look. Since I have an Owncloud instance running on a Raspberry Pi at home that I already use for exchanging files between PCs, privacy and confidentiality was not an issue. Also, there are Owncloud file synchronization apps available for the major mobile platforms. So I went ahead and installed the Owncloud client on two mobile operating systems to play around with it. Usage is straight forward and the apps offer full control over which files are transferred (and when) and which files are kept in sync. File transfers work just as they should and while I'm at home, my DSL router recognizes that the public destination IP address is bound to the WAN interface and reflects the packets right back into the network without a hop on the outside. That makes file transfers as fast as my home Wi-Fi allows. When not at home, transfer speed is limited to the speeds I can get over the cellular network and the 25 Mbit/s downlink and 5 Mbit/s of my VDSL connection at home. That's still good enough for most file sizes.

When I think back a couple of years ago, getting continuous and affordable Internet connectivity when traveling outside my home country was often quite difficult. Prepaid SIM cards were difficult to get, mobile data options were difficult to activate on those SIMs, some countries didn't have them at all, data roaming was prohibitively expensive and most hotel Wi-Fi was just plain crappy. In other words it took effort and a bit of luck to stay connected in a way that allowed working with a notebook and using VoIP and video software such as Skype. But my recent experience gives me hope that we have reached the tipping point.

On several of my recent trips, hotel Internet was quite o.k., even in the evening when lots of people use it. Sure, it's not like a VDSL line at home but there was always a megabit or two available and usually also enough in the uplink direction. So perhaps hotels are learning. In Europe mobile data roaming has also become affordable enough that one can rely on it for mobile connectivity outside the hotel for smartphones and moderate PC use. Offline navigation and mapping apps such as Osmand (Openstreetmap for Android) help. And local prepaid SIMs are often sold at airports now by knowledgeable staff that can activate data options and even configure APNs in case the smartphone doesn't configure itself correctly (noticed in Hong Kong, Korea and Malta recently). With data options ranging for half a gigabyte and up for around 10 to 15 euros with usable speeds of the cellular networks they are a good alternative or supplement to hotel Wi-Fi.

Pretty much exactly one year ago I had a post about a new handy little gadget from Edimax to distribute the hotel Wi-Fi or Ethernet connection to all my devices. It's convenient, I don't have to type in passwords on all devices and in case I have no choice but having to select a hotel with paid Wi-Fi a single payment enables access for all devices. Over time I came to use the little Wi-Fi router a lot but it has its quirks and I often ended up pressing the factory reset button and fiddling around with the configuration for a while before I got it working. At some point I felt it was time to have a look if there are other alternatives available in the meantime. And indeed there are now.

In the end I chose the Asus WL-330 N150 as it is almost as small as the previous one and cost around €30. So far it does its job quite well. Setting it up for use when arriving at the hotel is still a bit tricky. The average user wouldn't have a lot of fun with it as the device is sometimes a bit slow to react before the web based interface shows up and does what was requested. But once set up the Wi-Fi connectivity seems to be stable, at least in the two hotels I've tried it out so far.

In recent weeks I've been abroad a couple of times so I took advantage of the dual SIM capability of my current device. While I used my home country SIM for incoming and some outgoing calls I put a local SIM card in the second slot for Internet connectivity. While in most situation this worked like a charm I was almost defeated a couple of time by deep indoor situations with 2G only coverage. So what can be done? Fortunately I had another smartphone with me and another SIM card for Internet connectivity. Conveniently placed near a window there was still enough coverage there to restore my Internet connectivity via Wi-Fi covering. Yes, I know, I am taking this to the extreme... but 2G network coverage just doesn't cut it anymore when it comes to connectivity. That time has come and gone.